passthru.hpp

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/*
 * Copyright 2020 Robert Bosch GmbH
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#pragma once
 
#include <string>   // for string
#include <utility>  // for move
 
#include <fable/schema/ignore.hpp>     // for Ignore
#include <fable/schema/interface.hpp>  // for Base<>, Box
 
namespace fable::schema {
 
template <typename P>
class Passthru : public Base<Passthru<P>> {
 public:  // Types and Constructors
  using Type = Conf;
  using PrototypeSchema = std::remove_cv_t<std::remove_reference_t<P>>;
 
  Passthru(Type* ptr, std::string desc)
      : Passthru(ptr, PrototypeSchema(nullptr, ""), std::move(desc)) {}
  Passthru(Type* ptr, PrototypeSchema prototype, std::string desc)
      : Base<Passthru<P>>(prototype.type(), std::move(desc)), prototype_(std::move(prototype)), ptr_(ptr) {
    prototype_.reset_ptr();
  }
 
 public:  // Overrides
  [[nodiscard]] std::string type_string() const override { return prototype_.type_string(); }
 
  [[nodiscard]] Json json_schema() const override {
    Json j = prototype_.json_schema();
    this->augment_schema(j);
    return j;
  }
 
  bool validate(const Conf& c, std::optional<SchemaError>& err) const override {
    // Let the prototype do all the validation, since Passthru doesn't have
    // enough information to do a correct validation.
    return prototype_.validate(c, err);
  }
 
  using Interface::to_json;
  void to_json(Json& j) const override {
    assert(ptr_ != nullptr);
    j = **ptr_;
  }
 
  void from_conf(const Conf& c) override {
    assert(ptr_ != nullptr);
    *ptr_ = deserialize(c);
  }
 
  [[nodiscard]] Json serialize(const Type& x) const { return *x; }
 
  [[nodiscard]] Type deserialize(const Conf& c) const { return c; }
 
  void serialize_into(Json& j, const Type& x) const { j = serialize(x); }
 
  void deserialize_into(const Conf& c, Type& x) const { x = deserialize(c); }
 
  void reset_ptr() override { ptr_ = nullptr; }
 
 private:
  PrototypeSchema prototype_;
  Type* ptr_{nullptr};
};
 
template <typename S>
Passthru<Ignore> make_schema(Conf* ptr, S&& desc) {
  return {ptr, Ignore(), std::forward<S>(desc)};
}
 
template <typename P, typename S>
Passthru<P> make_schema(Conf* ptr, P&& prototype, S&& desc) {
  return {ptr, std::forward<P>(prototype), std::forward<S>(desc)};
}
 
}  // namespace fable::schema